Arabic القيروان (also known as Kairwan, Kayrawan, Al Qayrawan) is a Muslim holy city which ranks fourth after Mecca, Medina and Jerusalem as a place of pilgrimage. It is reputed that seven visits here are the equivilent of one to Mecca.It's large mosques and cultural history have seen it added to the UNESCO World Heritage List
Busses run to Kairouan from the major cities, Tunis, Sousse, Sfax
NB: Touts from the carpets shops have been known to board the bus a few km outside the city and befriend tourist to lure them into their shops, it is good to be aware of this fact
Louages run from many destinations into Kairouan, these are probably the best and most frequent way to get into the city.
Kairouan is not located on a train line.
The stations for both busses and Louagges are to the North West of the Medina. Though they may well drop you off at a Medina Gate if requested.
The Medina is best explored on foot, partially to absorb the atmosphere and partially because some areas are inaccessable to anything bigger.
Many of the shops near the main mosque will tempt you in with views over the complex, expect to have a look around the shop on the way out, if you don't buy anything a small donation would be polite.
A typical Medina Street
The Great Mosque is one of the finest Islamic buildings in North Africa and rewards closer inspection. Non Muslims are not permitted into the prayer hall, but the doors are open to allow you to view inside. Access to the main courtyard is available to all. The columns throughout the complex were taken from Carthage.
The Mosque of the Three Doors, has a one of the finest facades in Tunisia, though the interior is not open.
Medressas There are several of these Islamic Schools in the center of town that open up to visitors.
Bi'r Barouta, this Well is the place where the city was founded, it is reputedly linked to the ZamZam well in Mecca, it is one of the holiest sites in the city for Muslims.
Medina in general is a nice place to just wander around aimlessly, if it looks familiar it may well be as it was used in Raiders of the Lost Ark to double as Cairo.
The town is not big so you don't need to use transport. All places of interest are situated not far from hotels. 
Sit and enjoy a tea in a traditional tea house if the heat gets a little too much.
Carpets, Kairouan is particularly famous for its carpets and visiting a shop is an integral and sometimes unexpected part of visiting the city. Carpets are graded by their fineness, the number of knots in a square meter, with a normal weave from 10,000 to 40,000, fine weave from 65,000-90,000 and extra fine from 160,000 - 500,000. Silk carpets may be over 500,000 knots per square meter.
A speciality of Kairouan is the sticky pastry makrouhd, it can be found all through Tunisia.
There are a few nice Tea Houses on the road from the Main Gate into the centre of the city
Amina, Route de Tunis GP 2, Tel : (77) 226 555 / 235 466, Fax : (77) 235 411.